1. Field of the Invention
The present invention relates to overvoltage protection for communication systems, and in particular, to a combined overvoltage station protector apparatus having maintenance termination and a half ringer circuit arrangement disposed therein.
2. Discussion of the Relevant Art
The art abounds with many overvoltage protection systems utilized on telecommunication lines to protect them from overvoltages, such as caused by lightening strikes, typical of which is U.S. Pat. No. 5,224,013, issued to Emanuel J. Pagliuca on Jun. 29, 1993. One attempt to miniaturize the known devices, and include therein a maintenance termination unit (MTU), is disclosed in a miniature device described in U.S. Pat. No. 5,175,662, issued to Debalko, et al. on Dec. 29, 1992. However, the unit disclosed therein relates to a module utilizing an eight pin plug generally used in a telephone central terminal, which may readily be plugged in and out of a protection console. The device provides for the disconnection of the customer's line from the telephone network lines in order to determine if the problem is on the customer's side of the line or on the network side of the telephone line equipment.
Overvoltage protection devices are utilized to short the incoming signals to ground when an excessive voltage or current appears on the telephone line. Typically these units are mounted in separate housings proximate to the customer's home.
The present invention advances the state of the art by further combining the overvoltage protection with maintenance termination and half ringer circuitry.
The present invention includes all the features disclosed in the prior art, and in addition includes the known circuitry for a half ringer, which provides a minimal load to the telephone line at all times for testing purposes.
Therefore, it is the primary object of the present invention to reduce the size and number of packages that are required to provide the three separate functions together in a single housing.
It is another object of the present invention to provide a relatively small, reliable housing into which is placed overvoltage protection, maintenance termination and half ringer circuitry.
Other objects and advantages will become obvious to those knowledgeable in the art.